Our aim is to continue series of investigations into the role of autonomic nervous system in bronchial asthma. Specifically, the objective is to test the hypothesis that there is an altered uptake of catecholamines in the lungs of patients with this disease. In addition, the activation and inhibition of the sympathetic and parasympathetic nervous system in the lung will be studied. Asthmatic patients, on and off steroids, and healthy control subjects will be infused labelled catecholamines and their uptake and metabolism measured under different conditions. In a complementary series of experiments interaction between the sympathetic and parasympathetic nervous system will be explored on an isolated perfused animal lung model.